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Se describen los grupos de Escherichia coli enteropatógena, con especial atención a EC. enterohemorrágica. Algunos serotipos de E. Coli verotoxigénica son capaces de producir enteritis hemorrágica, que puede complicarse con el síndrome hemolítico urémico. Esta complicación, se da en particular en los niños y presenta una elevada letalidad. La transmisión a través de los alimentos y la capacidad de producir brotes epidémicos junto a la gravedad de las complicaciones de las enteritis confieren a este microorganismo una gran importancia en salud pública. Se revisa la epidemiología del microorganismo en nuestro país.

Unlabelled: Prophylactic and pre-emptive therapy with oral valganciclovir for cytomegalovirus infection in renal transplant recipients., Background: Cytomegalovirus infection is a very important health problem in solid organ transplant recipients (SOT). Once-daily valganciclovir has been shown to be as clinically effective and well tolerated as oral ganciclovir tid in the prevention of CMV infection in high risk SOT recipients., Methods: The aim of the present study was to evaluate the incidence and severity of CMV disease in 150 renal transplant recipients that received either prophylactic [high risk group (HR), N = 66] or pre-emptive [low risk group (LR), N = 84] therapy with oral valganciclovir (900 mg/day vo) for three months according to their basal risk. Patients were monitored for signs and symptoms of CMV disease and CMV plasma viral load was assessed weekly., Results: A total of 31 patients (47%) of the HR and 26 patients (31%) of the LR presented a positive CMV PCR result. Twelve patients (14.3%) in the LR that had a high viral load (CMV PCR > 1,000 copies/mL) but remained asymptomatic received pre-emptive therapy. Four patients (4.7%) in the LR, after an average time of 35 days after transplant and two patients (4.5%) in the HR, after prophylactic treatment was completed, developed CMV disease. The disease was mild-moderate in most of the cases. Those patients that developed CMV disease responded to treatment with iv ganciclovir for 14 days followed by treatment with oral valganciclovir for up to three months., Conclusion: Prophylactic treatment with oral valganciclovir for CMV prevention is only required in high risk solid organ transplant recipients.

In vitro susceptibility to acyclovir of 96 strains of herpes simplex virus isolated from 80 immunocompromised patients attended in our hospital was studied by the cytopathic effect reduction assay. Ninety-eight percent (61/62) of herpes simplex virus 1 strains and 91% (31/34) of herpes simplex virus 2 strains were inhibited by acyclovir concentrations lower than 3 mg/l. In 5% of the patients herpes simplex strains resistant to acyclovir (ID(50) >3 mg/l) were isolated. Ninety-eight percent of the lesions caused by herpes simplex viruses susceptible to acyclovir (ID(50) <3 mg/l) resolved independently of treatment. In two cases, the cytopathic effect reduction assay was not able to predict treatment failure and persistance of the lesions was not always associated with isolation of a resistant strain in vitro. In four cases, isolation of a strain resistant to acyclovir was not indicative of treatment failure. In conclusion, we believe there is no need to routinely test susceptibility of herpes simplex viruses to acyclovir and that susceptibility testing should be indicated only in patients in whom lesions persist and other causes have been ruled out.

Background: The purpose of this study was to find out the incidence and characteristics of H. influenzae type b invasive disease (HibID) in Catalonia, Spain., Material and Methods: An active surveillance of H. influenzae isolated from normally sterile sites was carried out during 1996. Microbiology laboratories of hospitals of Catalonia were periodically contacted by telephone. The serotype of all the strains was studied., Results: The incidence of H. influenzae invasive disease (HIID) was 7.1 per 100,000 in children under 5 years and 1.0 per 100,000 in those over 5 years. The incidence of serotype b was 6.4 per 100,000 children under 5 years and 0.2 above this age. Only three strains belonged to types other than b (d, e and f)., Conclusions: The incidence of HIbID is uncommon in Catalonia, lower than that registered in the prevaccine era in other countries and regions of the same geographical area.

Background: Bacterial meningitis is a severe infection of the central nervous system (CNS), most frequently caused by Neisseria meningitidis in our setting. Microbiologic diagnosis of bacterial meningitis is not enough sensitive because its efficiency can be affected by the therapeutic regimen given to the patient. Polymerase chain reaction (PCR) can provide a more sensitive diagnosis and allow us to get an earlier result., Objectives: To assess the sensitivity and specificity of a PCR technique for the diagnosis of meningitis caused by N. meningitidis and Haemophilus influenzae., Material and Methods: Ninety-six patients who were attended because of suspected bacterial meningitis on the Hospital de Sant Joan de Déu, Corporació Sanitària Parc Taulí and Hospital de la Santa Creu i Sant Pau, and had negative results by conventional laboratory methods, were selected for the study. A total of 99 cerebrospinal fluid samples (CSF) were obtained and evaluated for PCR. DNA extracts of the CSF samples were amplified by universal primers. Amplification products were hybridized with specific probes for Haemophilus genus and N. meningitidis. Positive and negative controls were included to asses the reliability of PCR., Results: Eight of the 99 CSF samples (8%) were positive by PCR and subsequent hybridization with the specific probe of N. meningitidis. None of the amplicons hybridized with the probe of Haemophilus genus. Thirteen percent of the patients (8/59) with clinical suspicious of non-neonatal sepsis or meningitis were diagnosed by PCR, amongst them, 36% of the cases (4/11) with initial diagnosis of meningococcal sepsis or meningitis., Conclusions: The sensitivity and the specificity of the PCR technique afford a complementary method to conventional ones, in special for the diagnosis of meningococcal meningitis in the group of pediatric patients.

We report three patients who developed a generalized rash with oral, genital or perianal ulcerations as a result of acute infection due to HIV. The primary infection was diagnosed by seroconversion (by means of EIA and Western blot techniques). Definitive diagnosis was established on days 52, 85 and 97 after the appearance of the rash. The p24 protein of the HIV was only detected in the early phase of the disorder in the two cases in which this study was carried out.

Objective: To determine the number of strains of classic enteropathogenic E. coli (EPEC) that have the eae gene, that is considered a pathogenicity factor., Material and Methods: The presence of the eae gene has been evaluated on 62 EPEC strains of ten different serogroups, isolated from children with gastroenteritis., Results: Amplification of the eae gene was positive in 10 out of 62 EPEC strains analyzed (16%) corresponding to seven different serogroups., Discussion: The low frequency of the detection of the eae gene on EPEC strains shows the limited correlation between the pathogenicity and the serogroup of the strains and would corroborate the need to reexamine this subject prospectively in our country.

Groups of Escherichia coli enteropathogen are described, with special attention to Escherichia coli enterohaemorragic. Some serotypes of Escherichia coli verocitotoxin-producing are able to produce haemorrhagic enteritis, which can develop a complication with hemolityc uraemic syndrome. This complication is most frequent in children and has a high mortality rate. The transmission takes place via food and its capacity to cause epidemic outbreaks together with the seriousness of the complications caused by enteritys make this microorganism of great importance to Public Health. The epidemiology of this microorganism in Spain is reviewed.

Background: The aim of the study was to describe the etiology of enteropathogenic agents over a four-year period (1992-1995) in a University Hospital in Barcelona., Methods: We studied 12,793 stool samples, 4519 were obtained from patients under 15 years and 8274 were obtained from patients over 14 years. The specimens were examined for bacteriological, parasitological and virological enteropathogens., Results: In 3380 specimens of 12,793 stool samples studied were identified an enteropathogen (26.4%). Polymicrobial associations were observed in the 6.8% of the cases. Pathogens were identified in 45% of children samples and 16.3% of adults samples. The etiological enteritis agents more frequently detected in the paediatric patients were Campylobacter (13.5%), rotavirus (11.3%) and Salmonella (10.2%); and Salmonella (4.9%), Campylobacter (3.1%) and Giardia intestinalis (2.1%) in adults. Cryptosporidium (13.5%) was the most frequent cause of gastrointestinal tract infections in HIV-infected subjects. In the children with stools positives, the presence of red and white blood cells were more frequent than the adults with stools positives (73% versus 26.6%)., Conclusions: The enteropathogenic agents such as Campylobacter, Salmonella, and Giardia were the most frequent cause of gastroenteritis in our environment. In the children, rotavirus infections predominated during the cold months. The most frequent cause of gastroenteritis in HIV-infected patients was Cryptosporidium followed by Campylobacter.

Background: Erythema induratum of Bazin (BEI), is included in the group of cutaneous granulomatous lobulillar panniculitis. The aethiopathogenic association between EI and tuberculosis can not rely on the clinicohistological features of these panniculitis and M. tuberculosis has never been isolated from BEI lesions. Detection of the mycobacterial DNA by PCR on cutaneous biopsy samples would allow to confirm this association., Patients and Methods: Fourteen patients with clinical BEI were chosen retrospectively. Seventeen lesional biopsy samples were obtained, stained with the Kinyoun carbolfuchsin acid-fast technique and haematoxylin and eosin and tested by PCR. A fragment of the IS6110 insertion sequence specific of M. tuberculosis was amplified and confirmed by digestion with Sal I restriction endonuclease. The efficiency of the procedure, the presence of inhibitory substances and the preservation of DNA were checked by PCR of the beta-actin gene., Results: M. tuberculosis DNA was detected in 12 of the 17 samples tested (70.5%) which corresponded to 10 of the 14 patients (71.4%). According to beta-actin PCR results, the rate of extracted DNA was inadequate on four of the five negative biopsies., Conclusions: The results of these series suggest the probable involvement of M. tuberculosis on the BEI pathogenesis and give support to the usefulness of the PCR in the diagnosis of this pathology concerning the need of specific treatment.

Objective: To describe the clinical and epidemiological characteristics of nine patients with enteritis caused by verocytotoxin-producing E. coli O157., Patients and Methods: Clinical data of patients was collected retrospectively, the isolated strains were tested for verotoxin production (VT) using Vero cell culture line, and presence of VT1 and VT2 gene sequences was detected using amplification techniques (PCR), biotype was also determined using twelve biochemical tests, and genomic macrorestriction profile (PFGE)., Results: The patients' age ranged from 11 months to 70 years. The mean duration of diarrhea was 4.7 days. All patients but one had abdominal cramps, seven of nine reported hemorrhagic stools and six had fever. Three patients were affected of haematologycal neoplasia and two of them developed hemolytic-uremic syndrome as a complication. All strains produced VT2 and two of them also produced VT1. Epidemiological link between patients has not been established. Three different biotypes had been distinguished between the nine isolated strains. All but two had different macrorestriction profiles., Discussion: The results obtained showed that clinical manifestations are rather inespecific, including fever (6/9 patients) and there is high association of severe complications. The heterogeneity in PFGE results obtained confirms that the cases are not related.

Hemorrhagic colitis is an enteritis caused by verotoxigenic strains of Escherichia coli. Conventional diagnosis requires the identification of the microorganism and the demonstration of verotoxin production. The determination of toxigenicity in isolated strains and in direct stool samples by the polymerase chain reaction (PCR) technique may simplify the diagnosis. Conventional coprocultures were performed for the detection of verotoxigenic E. coli O157:H7 from three stool samples of a patient with hemorrhagic colitis and hemolytic-uremic syndrome. The production of verotoxin was determined by cell culture and the presence of VT1 and VT2 genomic sequences by PCR. Likewise, the latter technique was applied to a direct stool sample for detection of the verotoxin codiying genes. The specificity of the amplified sequences was confirmed by enzyme restriction digestion. Escherichia coli O157:H7 was isolated in two of the three samples studied. The strains were toxigenic in the cell culture test at titers higher than 1/500 and PCR showed an amplified band of 479 pb corresponding to the VT2 codifying gene. The digestion of amplified sequences with the EcoRV enzyme led to two bands of 390 and 89 pb confirming the specificity of the results. One of the two stool samples studied directly by PCR was positive for VT2 with the result being obtained 48 hours after arrival to the laboratory. The preliminary results of this study give support to the usefulness of the polymerase chain reaction technique in the detection of verotoxin from isolated strains of Escherichia coli and in direct stool samples.

The reference technique for the diagnosis of active cytomegalovirus infection is the isolation in cellular culture. Its major drawback is the interval between the inoculation of the sample and the development of the characteristic cytopathic effect. Occasionally, this delay may be longer than four weeks. The centrifugation of the sample on the cell monolayer at the time of inoculation and the use of a fluorescein-labeled monoclonal antibody for the detection of the early antigen in cells may considerable reduce the time required for the diagnosis of cytomegalovirus infection. In the present study the technique of detection of the early antigen by immunofluorescence was compared with conventional cell culture in 258 clinical samples referred to the laboratory for study. Fifty-one of them were positive: 28 with both techniques, 12 only with cell culture and 11 only with immunofluorescence. The mean time to obtain positive results was 25 hours for immunofluorescence and 13 days for culture.